Neural sleeve for neuromuscular stimulation, sensing and recording

ABSTRACT

The present disclosure relates to neuromuscular stimulation and sensing cuffs. The neuromuscular stimulation cuff has at least two fingers and a plurality of electrodes disposed on each finger. More generally, the neuromuscular stimulation cuff includes an outer, reusable component and an inner, disposable component. One or more electrodes are housed within the reusable component. The neuromuscular stimulation cuff may be produced by providing an insulating substrate layer, forming a conductive circuit on the substrate layer to form a conductive circuit layer, adhering a cover layer onto the conductive circuit layer to form a flexible circuit, and cutting at least one flexible finger from the flexible circuit. The neuromuscular stimulation cuff employs a flexible multi-electrode design which allows for reanimation of complex muscle movements in a patient, including individual finger movement.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 16/877,554 filed May19, 2020 which is a continuation of U.S. Ser. No. 15/578,816 filed Dec.1, 2017 (now issued as U.S. Pat. No. 10,765,859) which is a nationalstage entry of PCT/US2016/035529 filed Jun. 2, 2016 which claimspriority to U.S. Provisional Patent Application Ser. No. 62/169,849filed Jun. 2, 2015, each of which is fully incorporated by referenceherein.

BACKGROUND

The following relates generally to systems, methods and devices forneuromuscular stimulation, sensing, and recording. Generally, the systemmay be used to receive thought signals indicative of an intended actionand provide electrical stimulation to nerves and/or muscles toeffectuate the intended action, thereby bypassing or assisting a damagedor degenerated region/pathway of the nervous system. The devices of thepresent disclosure are neuromuscular stimulation cuffs, also referred toherein as “neural sleeves,” which deliver stimulation to restoremovement to parts of the body not under volitional control due todamaged or degenerated neural regions/pathways from brain or spinal cordinjury, stroke, nerve damage, motor neural disease, and other conditionsor injuries. The system can also be used in a patient that has somelocal neural or muscle degeneration for therapeutic or rehabilitationpurposes.

Subcutaneous implantable neurostimulation cuffs have been commonly usedto block pain and to restore function to damaged or degenerative neuralpathways. These implantable cuffs are wrapped around a target nerve andgenerally include one or more electrodes arranged to stimulate thenerve. By including more than one electrode and/or a different geometryof electrodes, implantable cuffs such as the flat interface nerveelectrode (FINE) have been able to achieve stimulation selectivity atthe level of individual nerve vesicles.

Transcutaneous neurostimulation cuffs behave similarly to implantablecuffs, however there are important differences. Because the electrodesare placed on the surface of the skin, rather than below it, stimulationoften can better target skeletal muscle tissue or muscle groups, ratherthan peripheral nerves located deeper under the skin. Muscularstimulation may be preferable to stimulating major peripheral nerves,e.g. ulnar, median, radial nerves, as stimulating these nerves may causea patient to feel a tingling sensation and it is more difficult toeffect the desired movement. By increasing the number and layout ofelectrodes in a neuromuscular cuff, similar to the direction taken withimplanted nerve cuff designs, current generation neuromuscularstimulation cuffs have been able to selectively stimulate individualmuscles or muscle groups and achieve finer movements such as individualfinger flexing and extension.

Flexible-like transcutaneous cuffs have been developed which fit arounda human appendage such as a forearm to control the wrist or fingers.These flexible cuffs may include sensors which record muscle activity,or electromyography (EMG) signals, and stimulate in response to the EMGsignals. Thin film technologies have also become important in thedevelopment of functional electrostimulation (FES) devices. Devicesincorporating thin film technology are often based on a polyimidesubstrate covered by a chromium, gold, or platinum film.

Current transcutaneous neuromuscular stimulation electrodes (or patches)present many limitations. Such neuromuscular patches are typically large(several cm across or more) and have a single electrode (conductivesurface). This does not allow selective stimulation of small musclessegments for fine wrist and finger control.

It would be desirable to provide improved devices for neuromuscularstimulation. Flexible sleeves with multiple small electrodes would allowprogrammable spatial stimulation patterns, which is highly desirablewhen attempting to restore complex muscular movements throughneuromuscular stimulation.

BRIEF DESCRIPTION

The present disclosure relates to systems, methods, and devices forthought-controlled neuromuscular stimulation. Included is aneuromuscular stimulation cuff (i.e. “neural sleeve”) which receives athought signal indicative of an intended action, and in response,stimulates a damaged region/pathway of the nervous system to effectuatethe intended action. The neuromuscular cuff may include a flexibledesign, e.g., including a plurality of electrodes arranged on flexiblefingers. The flexible fingers allow for variable sized neuromuscularregions, e.g. paralyzed limbs, to fit within the neuromuscular cuff. Thefingers may also allow for increased electrode positioning choices forreanimation of complex muscle movements. The neuromuscular cuff mayfurther include an array of electrogel discs which provide enhancedelectrical contact as well as keep the cuff adhered to the skin duringstimulation-induced movement.

In yet other embodiments, a device for neuromuscular stimulationincludes a flexible printed circuit board having at least one finger anda plurality of electrogel discs disposed on the at least one finger.

In additional different embodiments, a method for producing aneuromuscular cuff includes providing a layer of polyimide, etching aconductive copper circuit including a plurality of electrodes into thelayer of polyimide to form an etched circuit layer, adhering a coverlayer onto the etched circuit layer to form a flexible printed circuitboard (PCB), and cutting at least one finger from the flexible PCB.

In other embodiments disclosed herein, devices for neuromuscularstimulation include: a reusable sleeve; and one or more electrodeshoused within the reusable sleeve.

In particular embodiments, the reusable sleeve comprises at least twoflexible fingers along which the one or more electrodes are located,each flexible finger extending in the same direction from a connector.Each finger contains one or more flexible conductive pathways that leadto the electrode(s) previously described. A plurality of conductivemediums is disposed on the flexible fingers to conduct the electricalimpulses from the electrodes. As a result, each flexible finger is ableto conform to different arm profiles and accommodate twisting of thearm.

The conductive medium may comprise a hydrogel, a lotion, or a conductivepolymer. The flexible fingers may be oriented with respect to theconnector so that they can be wrapped helically (e.g. around a patient'slimb). The device may further comprise a fabric layer disposed on anexterior of the reusable sleeve.

Each flexible finger may include a conductive circuit layer, which canbe arranged in the form of one or more conductive pathways. Thatconductive circuit layer may be laid upon an insulating base layer, forexample made of a polyimide. The flexible finger may include aninsulating cover layer over the conductive circuit layer. The flexiblefinger may include a plurality of hydrogel discs disposed over eachelectrode, wherein each hydrogel disk is independently connected to arigidizer. The rigidizer may interface with a processing device, such asa computer or other electronic device.

In other embodiments, a device for neuromuscular stimulation includes: areusable sleeve; multiple electrodes housed within the reusable sleeve;and an inner disposable sleeve, the inner disposable sleeve comprising aconductive medium in contact with the multiple electrodes.

The conductive medium may comprise a hydrogel which is relatively moreconductive in a z-direction than in a x-direction or a y-direction. Theconductive medium may be less conductive in a regular state; and theconductive medium may become more conductive upon application ofexternal pressure in a direction of the external pressure. Theconductive medium may include a compressible polymer and a conductivefiller dispersed in the compressible polymer. The conductive filler maybe carbon-based and comprise carbon fibers. The conductive filler maycomprise any of: carbon fibers, carbon nanotubes, or metallic particles(e.g. silver; gold; platinum; or palladium). The conductive medium maybe dry in an initial state and then become tacky upon any one of:application of an electrical current; a change in temperature; a changein pH; or a change in moisture. The conductive medium may include astimuli-sensitive polymer. Each electrode of the multiple electrodes mayinclude concentric rows of teeth about 200 μm to about 300 μm in height.The reusable sleeve may include a flexible material.

In other embodiments, the reusable sleeve may include: a rigid shell;and a hinge running parallel to a longitudinal axis of the reusablesleeve. Sometimes, the reusable sleeve may include a user interface forselectively configuring electrodes and adjusting stimulation level orpattern. The reusable sleeve may be expandable.

In other embodiments, the reusable sleeve may include a compressionsleeve fabric on which the multiple electrodes are printed usingsilk-screen technology employing conductive polycellulose orsilver/carbon-based ink. The device may further include a conductivepathway including an accelerometer.

The reusable sleeve may include a flexible circuit which may includeelectrodes connected by electrode traces; the electrode traces may housesensors; and the electrode traces may be arranged in a zig-zag patternto enhance flexibility and/or durability. The sensors may include anycombination of pressure sensors; strain gauges; accelerometers; amicro-electro-mechanical system (MEMS) including a 3-axis accelerometerand 3-axis magnetometer; a capacitive sensor including a flexibleinsulating dielectric layer sandwiched between flexible electrodes; astretch sensor including a material that changes electrical resistancewhen stretched or strained; a resonant bend sensor including aresistance-inductance-capacitance (RLC) circuit; a sensor including atleast one bladder configured to hold a fluid or air; a fiber optic cableand a measurement tool configured to measure a bend in the fiber opticcable based on a frequency or attenuation change in a signal of thefiber optic cable; and a video motion tracking system configured totrack a marker of the reusable sleeve.

The reusable sleeve may include conductive/carbon fibers and a dry fitmaterial. The reusable sleeve may be in the form of a fingerless glovemade of a stretchy material. The multiple electrodes may be woven intothe reusable sleeve using conductive threads. The reusable sleeve mayinclude buttons including light emitting diode (LED) based touchscreendisplays on a back side of each of the multiple electrodes. The reusablesleeve may include an accelerometer, and may be configured for gesturecontrol of devices. The reusable sleeve may be configured to cover botha leg portion and a foot portion of a patient; and supportgait-training. The reusable sleeve may include a shirt configured todeliver electrical stimulation to a backside of a patient. The multipleelectrodes may be configured to both deliver electrical simulation andsense a neural signal of a patient.

In another aspect, a device for neuromuscular stimulation may include: areusable sleeve; and multiple electrodes housed within the reusablesleeve; wherein the reusable sleeve comprises at least two flexiblefingers for housing the multiple electrodes, the flexible fingersextending in the same direction, and a plurality of conductive mediumsdisposed thereon.

In another aspect, a device for neuromuscular stimulation includes: areusable sleeve comprising a continuous substrate; and multipleelectrodes housed within the reusable sleeve; wherein the continuoussubstrate comprises a non-conductive portion and conductive, parallelpathways.

These and other non-limiting aspects of the present disclosure arediscussed in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a brief description of the drawings, which arepresented for the purposes of illustrating the exemplary embodimentsdisclosed herein and not for the purposes of limiting the same.

FIG. 1 is an overview diagram of one embodiment of a system forthought-controlled neuromuscular stimulation.

FIG. 2 is a block diagram for the decoding and re-encoding architectureoperating within the system of FIG. 1 .

FIG. 3 is a flow diagram for one embodiment of a method for providingthought-controlled neuromuscular stimulation.

FIG. 4 is a perspective drawing of a neural sleeve according to anexemplary embodiment, shown in place on a human arm.

FIG. 5 is a diagram for a concept design for fabricating one embodimentof the neural sleeve.

FIG. 6 is a diagram for an etched circuit layer for fabricating oneembodiment of the neural sleeve.

FIG. 7 is a close-up view diagram of the etched circuit layer of FIG. 6.

FIG. 8 is an alternative close-up view diagram of the etched circuitlayer of FIG. 6 .

FIG. 9 is a diagram for a coverlay layer used in fabricating oneembodiment of the neural sleeve.

FIG. 10 is a diagram for a silkscreen layer used in fabricating oneembodiment of the neural sleeve.

FIG. 11 is a stack-up diagram used in fabricating one embodiment of theneural sleeve.

FIG. 12 is a flow diagram for one embodiment of a method for producing aneural sleeve.

FIG. 13 is an exemplary photograph showing individual finger movementwithin a system for thought-controlled neuromuscular stimulation.

FIG. 14 is an exemplary photograph showing two neural sleeve devicesaccording to one embodiment disposed on a preparation bench.

FIG. 15 is an exemplary photograph showing two neural sleeve devicesaccording to the embodiment of FIG. 14 .

FIG. 16 is an exemplary photograph showing two neural sleeve devicesaccording to a different embodiment.

FIG. 17 is an exemplary photograph showing a rigidizer and the primaryside of a neural sleeve device according to yet another embodiment.

FIG. 18 is an exemplary photograph showing the positioning of apatient's arm region over two neural sleeve devices according to theembodiment of FIG. 14 .

FIG. 19 is an exemplary photograph showing two neural sleeve devicesaccording to the embodiment of FIG. 14 which are wrapped around apatient's arm region in preparation for neuromuscular stimulation.

FIG. 20 is an exemplary photograph showing two neural sleeve devicesaccording to the embodiment of FIG. 14 which are alternatively wrappedaround a patient's arm region in preparation for neuromuscularstimulation.

FIG. 21 is diagram of another exemplary embodiment of a neural sleeve.In this embodiment, conductive pathways extend from two differentconnectors. The fingers extend in the same direction, and taper towardsa center axis.

FIG. 22 is an exemplary illustration of a fingerless neural sleeve inthe form of a glove that can reach up to the elbow.

FIG. 23 is an exemplary illustration of a variation of the neural sleeveof FIG. 22 , in which the neural sleeve includes a user interface on theexterior in the form of buttons.

FIG. 24 is an exemplary illustration of a neural sleeve made of aflexible material with electrodes on the interior and implants forproviding directionality to the neural sleeve.

FIG. 25 is an exemplary illustration of a neural sleeve in the form of arigid shell having two hemicylindrical halves joined together by a hingealong the sidewall.

FIG. 26 is a cross-sectional illustration of a reusable neural sleeve,which is in the form of a flat flexible sheet that can be wrapped aroundthe arm.

FIG. 27 is an exemplary illustration of a neural sleeve with expandablebladders for pushing the electrodes against the skin. A handle can beincluded with the sleeve for proper registration/orientation of theneural sleeve.

FIG. 28 is an exemplary magnified illustration of the construction ofthe flexible conductive pathways of the neural sleeve. These pathwayscan include electrodes as well as other components, for example straingauges.

FIG. 29 is an illustrative diagram showing a neural sleeve applied tothe arm of a user. This particular neural sleeve is in the form of afingerless glove that covers the palm of the hand, extends past thewrist and the through the elbow up to the shoulder of the user. Thelocations of various sensors are highlighted in this diagram.

FIGS. 30A-41B are pictures of several different hand and arm motionsobtained from an experiment in which an able-bodied user was asked tomove his hand/arm into a given position. In each set, one picture showsan image of the hand/arm motion that the user performed with his limb,and the other picture shows a graphical hand representation of theuser's limb position based on position sensor data collected from thesleeve. In each set of pictures, the actual limb moved is shown as theleft hand, and the graphical limb moved is shown as the right hand.

FIG. 30A shows the limb moved for hand pronation, palm down, and FIG.30B shows the measured position in a graphical limb.

FIG. 31A shows the limb moved for perpendicular arm lift, and FIG. 31Bshows the measured position in a graphical limb.

FIG. 32A shows the limb moved for hand neutral position, and FIG. 32Bshows the measured position in a graphical limb.

FIG. 33A shows the limb moved for hand pronation, thumb down, and FIG.33B shows the measured position in a graphical limb.

FIG. 34A shows the limb moved for supination, palm up, and FIG. 34Bshows the measured position in a graphical limb.

FIG. 35A shows the limb moved for wrist extension, and FIG. 35B showsthe measured position in a graphical limb.

FIG. 36A shows the limb moved for wrist flexion, and FIG. 36B shows themeasured position in a graphical limb.

FIG. 37A shows the limb moved for radial deviation, and FIG. 37B showsthe measured position in a graphical limb.

FIG. 38A shows the limb moved for ulnar deviation, and FIG. 38B showsthe measured position in a graphical limb.

FIG. 39A shows the limb moved for finger extension, and FIG. 39B showsthe measured position in a graphical limb.

FIG. 40A shows the limb moved for finger fair curvature, and FIG. 40Bshows the measured position in a graphical limb.

FIG. 41A shows the limb moved for closing the fingers into a fist, andFIG. 41B shows the measured position in a graphical limb.

FIGS. 42A-42C are bar graphs showing the different percentages ofcurvature for each digit during finger extension, finger fair curvature,and making a fist. For each graph, 0 corresponds to the thumb, 1corresponds to the index finger, 2 corresponds to the middle finger, 3corresponds to the ring finger, and 4 corresponds to the pinky finger.The y-axis is the finger curvature percentage, and runs from 0% to 100%in intervals of 20%. FIG. 42A shows the percentages for fingerextension. FIG. 42B shows the percentages for finger fair curvature.FIG. 42C shows the percentages when a first is made.

DETAILED DESCRIPTION

A more complete understanding of the processes and apparatuses disclosedherein can be obtained by reference to the accompanying drawings. Thesefigures are merely schematic representations and are not intended toindicate relative size and dimensions of the assemblies or componentsthereof.

Although specific terms are used in the following description for thesake of clarity, these terms are intended to refer only to theparticular structure of the embodiments selected for illustration in thedrawings, and are not intended to limit the scope of the disclosure. Inthe drawings and the following description below, it is to be understoodthat like numeric designations refer to components of like function.

With reference to FIG. 1 and FIG. 2 , a system for thought-controlledneuromuscular stimulation may include a cortical implant 102 implantedinto the cerebral cortex region of the brain. The cortical implant 102in one embodiment includes a microelectrode sensing array, as depictedin FIG. 1 . The microelectrode sensing array includes multiple channels(e.g. 96 channels) and may be wired to an amplifier which furtheramplifies signals received by the microelectrode array. The corticalimplant 102 records “brain waves,” more particularly neural signalswhich are representative of a varied set of mental activities. Neuralsignals include electrical signals produced by neural activity in thenervous system including action potentials, multi-unit activity, localfield potential, ECoG, and EEG. These neural signals are sent wirelesslyor, alternatively, through a wired connection, from the cortical implant102 to a receiver on a neural signal processor device 104 for processingof the neural signals. In another embodiment, a scalp based interface,headset, or other sensor 102 picks up electroencephalogram (EEG) signalsand sends them to the receiver on the neural signal processor device104.

The neural signal processor 104 may include a processor including neuraldecoding algorithms 106 and/or control algorithms 108. These algorithms106, 108 allow for a received neural signal input to be decoded andsubsequently re-encoded for use in neuromuscular stimulation. Forexample, a received neural signal may be isolated to predict arm and/orhand movements a patient is thinking about. The neural signal processor104 may also include an oscilloscope or other signal waveform viewingand/or manipulation device. The neural signal processor also preferablyincludes an isolated pulse stimulator 111 which receives a processedsignal and generates a pulse signal for use in neuromuscular stimulationby an attached neuromuscular stimulation cuff 110.

With reference to FIG. 2 , the system for thought control at a morecomplex architectural level includes the cortical implant or sensor 102and the neural signal processor 104 which allow for the recording ofneural signals and the initial processing of the signals, respectively.Initial signal processing may include analog to digital conversion,normalization, and/or other filtering and processing methods known byone having ordinary skill in the art. Initially processed signals arethen decoded by the neural decoding algorithms 106. In exemplaryembodiments, the neural decoding algorithms 106 include force-basedalgorithms with firing-rate estimators.

The decoded signal output of the neural decoding algorithms 106 isfurther processed by the stimulation control algorithms 108. Inexemplary embodiments, the stimulation control algorithms 108 produce anoutput of peak current amplitude modulated, pulse width modulated, orfrequency modulated pulse trains going to the cuff electrodes. The pulsetrain can also be a non-stationary Poisson type train where averagepulse rate (frequency) is modulated. This may help reduce muscle fatigueas it more closely matches to the body's natural nervous system. Anexample of using poisson-distributed impulse trains to characterizeneurons in a region of the brain is disclosed in Pienkowski et al.,Wiener-Volterra Characterization of Neurons in Primary Auditory CortexUsing Poisson-Distributed Impulse Train Inputs, J. Neurophysiology(March 2009). Stimulation control algorithms 108 may be altered throughinput received from a training profile 107. The training profile 107 mayinclude training profile data representative of past user trainingsessions, e.g. motion demonstrations or coaching periods. Training datamay be used to alter and/or define simulation control algorithms 108during signal processing. Incorporating training data into stimulationcontrol algorithms 108 through a model-based approach yields moreaccurate decoding, e.g. patient thoughts accurately translated into acomplex motion, than prior position-based decoding efforts have shown.Additionally or alternatively, wrist-hand position feedback 109 may beused to alter and/or define stimulation control algorithms 108 duringsignal processing.

Signal control algorithm 108 output may be sent to the isolated pulsegenerator 111, where the signal is converted into a waveform that issuitable for neurostimulation. Suitable waveforms may include monophasicand biphasic pulses with a voltage between 80 to 300 Volts. However,even higher voltages may be used as long as safe current levels aremaintained and proper insulation is used. In exemplary embodiments, thewaveform is a monophasic pulse with a peak current of 0-20 mA which ismodulated to vary strength of muscle contraction, frequency of 50 Hz,and a pulse width duration of 500 ms. The output of the isolated pulsegenerator 111 is sent to the neuromuscular stimulation cuff 110 todeliver functional electrostimulation to the patient.

With reference to the flow diagram set forth in FIG. 3 , a method forproviding thought-controlled neuromuscular stimulation S100 starts atS101. At S102 neurological signals are received from a patientindicative of an intended action. For example, neurological signals maybe received though cortical implant 102. At S104 the neurologicalsignals are processed, which may include analog to digital conversion orfiltering. At S106, the digitized signals are decoded by at least oneneural decoding algorithm 106. At S108, the decoded signals areprocessed by at least one stimulation control algorithm 108. At S110,the method alternatively includes altering the stimulation controlalgorithms 108 by training data which is stored in the training profile107. At S112, the method alternatively includes altering the stimulationcontrol algorithms 108 based on movement data, e.g. wrist-hand positionfeedback 109. At S114, the output of the at least one signal controlalgorithm 108 is converted into a re-encoded signal consisting ofmultiple pulse trains, each pulse train going to a correspondingelectrode 114. At S114, neuromuscular stimulation is delivered to thepatient by sending the re-encoded signal to the neuromuscularstimulation cuff 110.

In another embodiment, the method for providing thought-controlledneuromuscular stimulation S100 further includes at S117 deliveringneuromuscular stimulation to the patient by selectively deliveringstimulation to at least one pair of electrodes 114 within aneuromuscular cuff 110 to effectuate the intended action.

In yet another embodiment, the method S100 further includes S103recording neurological signals from a patient. These neurologicalsignals may be sensed from, e.g., a forearm or wrist region with neuralpathway damage. Recording may also occur at a neurologically intactregion such as a functional leg, for which stimulation pulses can beprovided for stimulating commonly tied motions in damaged limbs, e.g.arms and legs. Commonly tied motions include hip and arm movements orpivoting movements. In the same embodiment, method S100 at S118 mayfurther include delivering neuromuscular stimulation to the patient byselectively stimulating to at least one pair of electrodes within theneuromuscular cuff 110 based on the re-encoded signal.

With reference to FIG. 4 , an exemplary embodiment of the neuromuscularstimulation cuff 110 includes a flexible printed circuit board (PCB) 112upon which electrodes 114 and hydrogel discs 116 are arranged in anelectrogel disc array 118. The neuromuscular stimulation cuff 110 fitsover a damaged or degenerative region 120 of the nervous system, e.g. apatient's arm as illustrated. The flexible PCB 112 acts as a substrateupon which the electrodes and other conductive materials are laid. Thisflexible base layer may be comprised of a single layer of a flexibleinsulating material, for example a polyimide material. Up toapproximately twenty electrodes 114 may be individually etched onto eachfinger 124 of the flexible PCB 112 as a copper layer. In exemplaryembodiments, the flexible PCB 112 has a total of eighty electrodes 114disposed over four fingers 124. The electrodes 114 may be subsequentlyplated with a conductive metal such as gold, palladium, or silver forgreater conductivity.

In some embodiments, electrodes 114 both stimulate a neuromuscularregion 120 by stimulating individual muscles and/or groups of muscles,as well as monitor or record skeletal muscle activity, specificallyelectromyography (EMG) signals. Sensed EMG data pertaining to a sensedmuscle target may be used in methods for closed or open loop stimulationof the muscle target. Sensed EMG data may also be analyzed in decidingwhether to reposition the neuromuscular stimulation cuff 110 within theneuromuscular region 120 or to turn off individual electrodes 114 withinthe electrogel disc array 118.

Hydrogel discs 116 may be rolled over the electrodes 114 to provideenhanced electrical and mechanical coupling. When appropriately aligned,the hydrogel discs 116 completely cover the electrodes 114 andeffectively form conductive electrogel discs 117. Put another way, theelectrodes are located between the base layer and the hydrogel discs.Electrical coupling is enhanced in that hydrogel provides greaterconductive contact with the skin than is achievable with a baremetal-plated electrode surface. Additionally, a carrier signal providedto any of the electrogel discs 117 in the electrogel array 118 mayconduct through the tissues of a patient and be released at any otherelectrogel disc 117 provided in the array 118. Enhanced mechanicalcoupling is provided through the exemplary adherence characteristics ofhydrogel to the skin. Hydrogel discs 116 may stay coupled to the skineven during complex patient movement. The hydrogel discs arecommercially available as a tape which may be rolled on an electrodesurface. One such example includes AmGel 2550 from AmGel Technologies.In the exemplary embodiment of the neuromuscular cuff shown in FIG. 4 ,the hydrogel discs are provided through custom spaced hydrogel discslocated on AmGel 2550 rolled hydrogel tape. In the alternative, insteadof hydrogel discs, a lotion or discs of a conductive polymer could beused.

The electrogel disc array 118 is spread over a plurality of fingers 124,wherein the fingers 124 are cut from the flexible PCB 112 to provideadditional flexibility in the placement of electrogel discs 117.Reanimation of complex motion may require stimulating muscles which arenot located directly along the dimensions of a conventionally shapedneuromuscular cuff 110. By wrapping fingers 124 around differentmuscular regions, e.g. the lower wrist and thumb, complex motions suchas thumb movement may be reanimated more effectively than with limitedplacement options.

FIGS. 5-11 are views of various layers of the neuromuscular stimulationcuff, and are separated for convenience and understanding. Withreference to FIG. 5 , one embodiment of the neuromuscular stimulationcuff device 110 (or neural sleeve) may be fabricated in accordance witha concept design 500. Dimensions of and between the various componentsof the concept design 500 are indicated in millimeters (mm). The conceptdesign 500 includes, as shown here, an insulating base layer, forexample made of a single layer of polyimide base material 522. In someembodiments, the polyimide base material is a DuPont AP8523E polyimidewhich is 50 μm (micrometers) thick and rolled-annealed copper clad at 18μm thick. This base material serves as a substrate for the other layersof the neuromuscular stimulation cuff. This base material is formed, forexample by cutting, into at least two flexible fingers. As illustratedhere, the base material 522 is cut into four fingers 524, where theelectrodes will be located or housed. The fingers can be attached toeach other, for example by five webbings 525 which run between adjacentfingers.

The fingers 524 extend in the same direction from the rigidizer 530,which acts as a connector for one end of the fingers. In other words,the ends of the fingers distal from the rigidizer are all located in thesame direction relative to the rigidizer, or put another way therigidizer 530 is at one end of the device. It is noted that the fingers524 are shown here as extending at a 90-degree angle relative to theconnector/rigidizer 530. It is contemplated that the flexible fingerscould extend at any angle from the connector 530. Referring back to FIG.4 , setting the flexible fingers at an angle from the rigidizer wouldpermit the flexible fingers to be wound helically around the arm anddown along the entire length of the arm.

The rigidizer 530 is used for interfacing with the neural signalprocessor 104. Drilled holes 531 are additionally located on therigidizer 530 which represent connector pin insertion points. Inexemplary embodiments, eighty drilled holes 531 are approximately 1.016mm in diameter with a tolerance of +/−0.05 mm. As illustrated here, thefingers 524 are parallel to each other along their entire length. Aswill be seen later, this is not a requirement.

If desired, an optional fork 526 can be located at the end of thefingers opposite the connector/rigidizer 530. The fork connects all ofthe fingers, and can be provided for structural support for design andmounting. Drilled holes 527 are provided in the fork 526 for supportand/or mounting purposes. In some embodiments, the four drilled holes527 are approximately 2.387 mm in diameter with a tolerance of +/0.076mm. Headers 528 extend between the rigidizer and the fingers. Theseheaders are thinner than the fingers, and connect the fingers 524 to therigidizer 530. The headers are also part of the overall flexible finger,though they are not always required. Though not illustrated, webbingscan also be provided between adjacent headers as well if desired. Again,as will be seen later, the fork 526 is optional, though the connector530 is required.

With reference to FIG. 6 , a conductive circuit layer 600 forfabricating the neuromuscular stimulation cuff device 110 is shown. Theconductive circuit layer 600 is located on the surface of the insulatingpolyimide substrate 622, upon which copper electrodes 640 and connectivecopper traces 642 are formed to make a conductive pathway, for exampleby etching, deposition, ablation, etc. The electrodes 640 and traces 642run along the four fingers 624 of the substrate 622. The traces 642 runlongitudinally down the four headers 628 to electrically connect theelectrodes 642 to the connector/rigidizer 630. Again, theconnector/rigidizer 630 is used for interfacing with the neural signalprocessor 104. The traces 642 continue onto rigidizer 630 and end, inthis exemplary embodiment, at eighty connective points 632, whichrepresents twenty connective points 632 per finger 624. Each of theeighty connective points 632 corresponds to an individual electrode 640,electrically connected through an individual trace 642.

FIG. 7 is a closer view of the conductive circuit layer 600 of FIG. 6 .The substrate 622, electrodes 640, and traces 642 are more particularlyseen here. Each electrode 640 is individually connected to a singletrace 642, and the trace 642 runs down header 628 to theconnector/rigidizer 630 (not shown). In some embodiments, the traces 642are approximately 0.127 mm in width. As illustrated here, each electrode640 includes at least one ear 641 which is used to support the electrode640 upon the insulating substrate 622. As seen here, each electrodeincludes a central area 643 and three ears 641. The central area has acircular shape, and is used as an electrical contact. Each ear extendsbeyond the perimeter of the central area. As illustrated here, two earsare separated by 60 degrees, and are separated from the third ear by 150degrees.

Referring to FIG. 8 , the conductive circuit layer illustrated in FIG. 6may include electrodes 640 that are approximately 12 mm in diameter (notcounting the ear) and spaced 15 mm apart. This 15 mm spacing betweenelectrodes would dictate the custom spacing required for subsequentapplication of hydrogel discs 114.

FIG. 9 illustrates an insulating cover or “coverlay” layer 700 whichwould be placed over the electrodes and traces. The coverlay layer canbe made from a single layer of an insulating material such as polyimide722, which is preferably thinner than the substrate upon which theelectrodes and traces are copper-etched or otherwise formed. In oneembodiment, the coverlay layer is a DuPont LF0110 polyimide materialwhich is a 25 μm thick coverfilm. A further thickness of 25 μm ofacrylic adhesive can be used for adhering the coverlay layer 700 to theconductive circuit layer 600. The coverlay layer also includes a fork726, fingers 724, headers 728, and rigidizer section 730 whichcorresponds to these areas on the base substrate 522 and the conductivecircuit layer 600. Cutouts 740 are left in the fingers to expose thecentral area of the electrodes, and on the rigidizer section 730 for theelectrical connectors.

The insulating cover layer 700, when applied over the conductive circuitlayer 600, covers the copper traces 642 formed on the fingers 724 andthe headers 728. The coverlay layer 700 does not cover the central area643 of the electrodes, but does cover the ears 641, thus fixing theelectrodes in place between the substrate and the coverlay layer. Inaddition, the electrical connectors in the rigidizer section 730 willremain uncovered. The exposed central areas of the electrodes 640 arepreferably plated with a conductive metal such as tin, platinum, orgold. In one embodiment, exposed copper electrodes are plated withelectroless-nickel-immersion-gold (ENIG) at the level of 3-8 μm goldover 100-150 μm nickel.

FIG. 10 is a diagram for a silkscreen layer 800 that can be used infabricating the neuromuscular stimulation cuff device 110. Thesilkscreen layer 800 is applied to the combination of the conductivecircuit layer 600 and coverlay layer 700 to identify individualelectronic elements. A first silkscreen identification number 850 isprovided to each electrode 840 so that it may be more easily found aftervisual inspection. In one embodiment, first silkscreen identificationnumbers 850 span from A1-A20 and D1-D20 to represent eighty individualelectrodes 840. A second silkscreen identification number 852 identifiesthe connection ports for a rigidizer 830. In one embodiment, secondsilkscreen identification numbers 852 span from J1-J4. Both first andsecond silkscreen identification numbers 850, 852 are provided on asecondary side of the neuromuscular stimulation cuff 110, or side facingaway from exposed electrodes 740. In an exemplary embodiment, silkscreenidentification numbers 850, 852 are provided by white epoxynonconductive ink.

Referring now to FIG. 11 , various embodiments of the neuromuscularstimulation cuff device may be fabricated according to stack-up diagram900. An insulating base material (e.g. polyimide) provides a substrate950 upon which various components are fixed. A secondary side rigidizer830 is laminated to a secondary surface of the substrate 950. Theconductive circuit layer 600 is fabricated onto a primary surface of thesubstrate (opposite the secondary surface), and includes electrodes andtraces that form conductive pathways on the flexible base substrate. Thecoverlay layer 700 is subsequently adhered to the conductive circuitlayer 600 which covers the traces and leaves exposed portions of theelectrodes. The combination of the substrate 950, conductive circuitlayer 600, and coverlay layer 700 is defined as the flexible finger 912.Primary rigidizer 730 is stacked upon the coverlay layer to complete theelectrical connection required to interface the flexible finger with theneural signal processor 104.

With reference to the flow diagram set forth in FIG. 12 , one embodimentof a method for producing a neuromuscular cuff S200 starts at S201. AtS202 a single layer of polyimide base material 950 is provided. At S204,a conductive circuit layer is fabricated onto the polyimide basematerial 950 by etching a conductive copper circuit into the polyimide.At S206 a polyimide coverlay layer 700 is adhered to the conductivecircuit layer 600. Adhering the coverlay layer 700 to the conductivecircuit layer 600 completes the formation of a flexible PCB from whichthe flexible conductive pathways 912 will be formed. At S208, aplurality of flexible fingers are formed from the flexible PCB toprovide additional contact points for stimulation of muscles or sensingEMG signals. At S210, finger webbings 725 may optionally be cut from theflexible PCB to separate the flexible fingers and provide additionalflexibility, such as to accommodate limb twisting (such as the forearm)while maintaining contact. At S212, hydrogel may optionally be rolledover the electrodes to create electrogel discs 117. At S214, a rigidizer630, 730, 830 is attached to the flexible fingers 912 for interfacingwith the neural signal processor 104. At S216, the flexible fingers 912are interfaced with the neural signal processor 104.

With reference to FIG. 13 , individual finger movement within a systemfor thought-controlled neuromuscular stimulation 1000 is demonstrated. Aneuromuscular cuff 1010 according to one embodiment is wrapped over adamaged or degenerative region 1020 of the nervous system. Theneuromuscular cuff 1010 is interfaced with a neurological signalprocessor 1004 through attached rigidizer 1030. The rigidizer isattached to a connection port 1005 on the neural signal processor 1004.Received neurological signals indicative of patient thinking aboutmoving their first two digits has been decoded and re-encoded into pulsetrain signals transmitted to various electrodes on the neuromuscularstimulation cuff 1010. Using a specific number and spacing ofelectrodes/electrogel discs 1017 in neuromuscular stimulation cuff 1010has allowed for high resolution and non-invasive neuromuscularstimulation which effectuates the intention of the patient.

Electrogel discs 1017 operate in pairs when reanimating motion.Individual digit movement may be effectuated through the operation oftwo to three pairs (4 to 6 units) of electrogel discs 1017 which arestimulating in tandem. Selecting particular pairs of electrogel discs1017 to reanimate motion as indicated by a decoded brain signal isadvantageously performed by the neuromuscular stimulation cuff 1010, aseach electrogel disc 1017 is connected to the neurological signalprocessor 1004 individually along a single traces etched into aconductive layer of flexible polyimide material.

With reference to FIG. 14 , two neuromuscular cuff devices 1010according to one embodiment are disposed on a preparation bench 1070.The preparation bench 1070 may be used to keep cuff devices 1010 flatand roll hydrogel tape across electrodes 1016. Properly adhered hydrogeldiscs 116 (not shown) should fully cover the surface of electrodes 1014.

With reference to FIG. 15 , two neuromuscular cuff devices 1010according to the embodiment of FIG. 14 are shown. The cuff devices 1010each include a fork 1026 for additional support when designing and/orplacing the cuff devices 1010 over a damaged or degenerativeregion/pathway of the nervous system (not shown). Again, the fork isoptional.

With reference to FIG. 16 , two neuromuscular cuff devices 1110according to a different embodiment are shown. A fork 1126 is providedat one end of each cuff for additional design and/or structural support,similar to the fork 626 in FIG. 6 . Here, a second fork 1127 is alsoprovided located along the headers 1128. Put another way, the flexiblefingers 1124 are bracketed by a fork on each end. The additional fork1127 provides additional support in combination with fork 1126 forsituations when the neuromuscular cuff 1110 must be stretched flatacross a surface. Additional fork 1127 can also maintains flexiblefingers 1124 within the same damaged or degenerative region/pathway 1120(not shown), which effectively concentrates stimulation and preventsflexibility.

With reference to FIG. 17 , the primary side of another embodiment ofthe neuromuscular cuff 1200 is shown. Hydrogel discs 1216 have beenapplied to electrodes 1214 (not shown, covered), forming an electrogeldisc array 1218. Two of the four flexible fingers 1224 still include thehydrogel tape before being separated from hydrogel discs 1216.Electrogel discs 1217 are not connected to each other within the array1218 so that the electrogel discs 1217 may be independently stimulated.

While not exposed to the air, copper traces 1242 are viewable throughthe polyimide cover layer 700. A secondary side rigidizer 1230 is shownby folding the primary side over at the headers 1228. Connectors 1234 onthe secondary side rigidizer 1230 allow for the neuromuscularstimulation cuff 1200 to be interfaced with the neural signal processor104 (not shown). Each pin 1236 within connector 1234 is electricallyconnected with a single electrogel disc 1217.

With reference to FIG. 18 , a patient's arm including damaged ordegenerative regions/pathways 1020 is placed over two neuromuscular cuffdevices 1010 according to the embodiment of FIG. 14 . Flexible headers1028 may be used as support while positioning the device 1010 under anarm.

With reference to FIG. 19 , two neuromuscular cuff devices 1010 in anexemplary embodiment are wrapped around a patient's arm region 1020 inpreparation for neuromuscular stimulation. The two cuff devices 1010together provide 160 separate electrodes for stimulating finger or wristmovements. The flexible fingers 1024 permit the neuromuscular cuff tofit around the arm region 1020 at points of varying circumference.Hydrogel discs 1016 (not shown) keep both cuffs 1010 adhered to the arm.

With reference to FIG. 20 , two neuromuscular cuff devices 1010according to the embodiment of FIG. 14 are alternatively wrapped arounda patient's arm region in preparation for neuromuscular stimulation.Only two flexible fingers 1024 of one of the neuromuscular cuff devices1010 have been applied, while all of the flexible fingers 1024 on theother cuff device 1010 are already wrapped around the patient's arm.More or less electrodes can be used, as shown in FIG. 20 , depending onthe nature of the damage to a patent's nervous system region/pathway1020 and the type of movement one wishes to reanimate throughneuromuscular stimulation.

In another exemplary embodiment, the flexible fingers of a neural sleeve2110 do not need to be straight for their entire length. Referring nowto FIG. 21 , flexible fingers 2124 extend from first connector 2130,which has a rectangular shape in this illustration. The flexibleconductive pathways 2124 in this embodiment “change” directions as theyextend from connector 2130. For example, an upper flexible finger 2124 afirst extends upwards from the connector 2130, then changes direction sothat its electrodes 2140 are to the right of the connector 2130. Acenter flexible finger 2124 b extends from the right-hand side of theconnector 2130 off to the right of the connector. A lower flexiblefinger 2124 c first extends downwards from the connector 2130, thenchanges direction so that its electrodes 2140 are also to the right ofthe connector 2130. Notably, none of the electrodes 2140 are present tothe left of the connector 2130.

This embodiment of a neural sleeve 2110 also contains more than oneconnector/rigidizer. As illustrated here, the neural sleeve 2110 has afirst connector 2130 and a second connector 2131. Flexible fingersextend in the same direction (here, to the right) of both connectors.Webbings 2135 connect flexible fingers extending from each connector2130, 2131. There may be any number of webbings 2135, and the webbings2135 may connect the flexible fingers at any portion of their length.Here, the webbings 2135 are present along a non-electrode-containingportion 2150 of the flexible fingers (i.e. the header portion). Thoughnot depicted, it is specifically contemplated that the flexible fingersof one connector 2130 may be of a different length from the flexiblefingers of the other connector 2131.

The electrodes 2140 may be evenly spaced apart along the length of theflexible fingers 2124, or their spacing may vary, for example becomingshorter or longer, as the distance from the connector 2130 increases.For example, muscle segments get smaller closer to the wrist, so theelectrodes need to be closer together as well. However, the electrodesdo not need to be present along the entire length of the flexiblefingers. As seen here, the flexible fingers 2124 may include anon-electrode-containing portion 2150 extending from the connector,which is similar to the header 528 of the embodiment of FIG. 5 . Theflexible finger may also include a non-scalloped electrode-containingportion 2160, and a scalloped electrode-containing portion 2170 at thedistal end of the flexible finger (i.e. distal from the connector). Itshould be noted that none of the flexible fingers overlap with eachother.

The electrode-containing portions 2160, 2170 of the flexible fingershave a different shape from each other. One reason for this differencein shape is because, as seen here, the distal ends of the flexiblefingers 2124 extend inwardly towards a center axis 2105 of the neuralsleeve 2110. Put another way, the flexible fingers 2124 taper inwardstowards the center axis 2105. The scalloped portions 2170 of adjacentflexible fingers permit them to fit into a smaller area while stillproviding a suitable number of electrodes (note the electrodes do notchange in size). However, the flexible fingers 2124 all still extend inthe same direction away from the connector 2130, i.e. to the right inthis figure. Put another way, the flexible fingers comprise a firstportion which is transverse to the center axis 2105, and a secondportion which is parallel to the center axis. These portions areparticularly seen in the flexible finger 2124 a, which first extendsupwards (i.e. transversely to the center axis), then extends parallel tothe center axis.

This particular embodiment is intended to be used on a patient's armwith the two connectors 2130, 2131 located near the shoulder, and thescalloped portions 2170 near the wrist and hand.

In other exemplary embodiments, it is contemplated that the neuralsleeve will include both an outer, reusable component, and an inner,disposable component. Advantageously, this allows for a reduced per-usecost for the outer component, while permitting multiple differentpersons to use the outer component without hygienic concerns. The outerreusable sleeve contains the electrodes.

It is contemplated that the outer sleeve/reusable component, in severalembodiments, could be made of a flexible, stretchy, and/or compressiblefabric material which would fit snugly against the user's arm. Thematerial could also be a dry-fit material, i.e. a material which canmove sweat away from the user's arm and permit the sweat to evaporate.The connector and flexible fingers would line the interior of the outersleeve. For example, conductive threads or fibers could be woven intothe fabric material. Alternatively, the conductive traces and electrodescould be printed onto the outer sleeve material using silk-screentechnology, for example using conductive polycellulose, a silver-basedink, or carbon-based ink.

FIG. 22 and FIG. 23 show one exemplary embodiment of this neural sleeve.FIG. 22 is an illustration of a neural sleeve 2210 which is in the formof a fingerless glove. The sleeve 2210 includes a thumb portion 2212that extends up past the base of the thumb. Electrodes 2240 are spacedthroughout the sleeve. Not visible in FIG. 22 is an inner sleevecontaining a conductive medium. FIG. 23 is an illustration of avariation on the neuosleeve outer component. As illustrated here, theneural sleeve 2310 has a user interface on the exterior reusablecomponent, which can be used for control (including registration,activation, configuration and so forth) of individual electrodes orgroups of electrodes, allowing a user to configure the electrodes oradjust a stimulation level or pattern. For example, the outer componentmay include buttons 2311 (e.g. in the form of LED-based touchscreens).While only four buttons are illustrated here, the user interface caninclude any number of buttons, and those buttons can be of any shape.

Another aspect of the present disclosure is illustrated in FIG. 24 . Theneural sleeve itself may be made in a bidirectional manner, i.e. bothends of the sleeve are of the same construction. It is contemplated thatdirectional implants 2402, 2404 could be used to provide directionalinformation to the neural sleeve 2410, e.g. which end of the neuralsleeve is closer to the elbow or the wrist. These implants may belocated in the patient's limb, or located at opposite ends of the neuralsleeve itself. Only one such implant is needed to identify theorientation/direction of the neural sleeve. It is noted thatthree-dimensional information can also be provided by such implants.Also depicted are the electrodes 2420.

FIG. 25 is another embodiment of the reusable outer component. Here, theouter component is in the form of a rigid shell 2510. The shell isseparated into two hemicylindrical halves 2512, 2514 which are joinedtogether by a hinge 2511. The hinge runs parallel to the longitudinalaxis 2505 of the shell. A closing mechanism 2516 is located on oppositeopen ends of the halves for keeping the shell closed once it is closedaround the user's limb. Within the shell is padding for conforming theshell to the user's limb, or a bladder that can be inflated with air.The shell houses the electrodes 2520 (which are used for both sensingand delivering neuromuscular stimulation), as well as other accompanyingelectronics. It is contemplated that the disposable inner component (notshown) is first applied to the inside of the shell, or reusable dryelectrodes are attached to the inside of the shell. Then the limb isplaced in the shell, the shell closes around the limb, and the softpadding conforms around the limb and applies pressure on the electrodesagainst the limb, or the air bladder is inflated to apply pressure tothe electrodes against the limb.

Alternatively, as seen in the cross-sectional view of FIG. 26 , theneural sleeve can be in the form of a flexible sheet 2610 which iswrapped around the user's limb 2601. The electrodes (not visible) arespaced throughout the flexible sheet, and a closing mechanism 2605 ispresent on opposite ends of the sheet. Such a mechanism may be, forexample, a hook-and-loop fastener.

FIG. 27 illustrates another potential embodiment of the neural sleeve.Desirably, the electrodes are fitted snugly against the patient's limb.In this embodiment, the neural sleeve 2710 contains bladders 2720 thatcan be filled with air or some fluid, causing the neural sleeve toexpand and push the electrodes 2730 against the limb. A pneumatic pumpcan be used to fill the bladders. A directional implant 2702 is alsopresent here at a distal end 2704 of the sleeve. In addition, a handle2740 is also present at the distal end of the sleeve. This handle isintended to help with registration of the electrodes in known positions,and also provides directionality to the neural sleeve.

In some embodiments, the neural sleeve is shaped so that electrodes canbe placed on the palm at the base of the thumb, where the thenar groupof muscles is located (“the thenar eminence”). These muscles controlmovement of the thumb, and it is believed that this may aid in evokingthumb opposition (movement of the thumb in the direction of the pinkyfinger). This could be accomplished, for example, by extending one ormore of the flexible fingers 2124 of FIG. 21 to extend for a shortdistance beyond the other flexible fingers to reach to the base of thethumb, whereas the remaining flexible fingers extend only to the wrist;or by placing electrodes 2240 of the glove of FIG. 22 in the base of thethumb; or by placing an electrode at the end of the handle 2740 on thedevice of FIG. 27 .

The neural sleeve can incorporate several different types of sensors toprovide information on data and feedback on the position and movementsof the limb and other body parts. For example, desired positioninformation from the sensors can include a 3-dimensional location (X, Y,Z coordinates) of various points on the hand and arm relative to thebody and to each other, and rotation information of the wrist, elbow,and shoulder relative to the body. Orientation of various body partswith respect to gravity can also be measured with an accelerometer (orinclinometer). Motions of the hand and arm may be derived from positionsensors or from independent sensors. Other desired information includesjoint angles at the elbow, wrist, thumb and fingers (or other bodyjoints). A variety of concepts for sensors may be used to measure one ormore of these data items. Broad categories of sensors includeaccelerometers, micro-electro-mechanical (MEMS), electronic (based onresistance, capacitance, or resonance), fluid bladders, optical fiberbend sensors, and video tracking systems. Again, these concepts can begenerally applied to a neural sleeve on any body part or limb (e.g. arm,hand, leg, foot, etc.).

FIG. 28 illustrates some aspects which can be used for sensing. This isa magnified picture of a flexible conductive pathway 2810. Electrodes2820 are present on the flexible conductive pathway. Here, fourelectrodes 2820, 2822, 2824, 2826 are illustrated. Electrode traces 2830are present between the electrodes. As seen here, the trace have azig-zag pattern, which can be used as a strain gauge.

In a first sensor aspect, integrated 6-axis MEMS (3-axis accelerometerand 3-axis magnetometer) sensors can be used to measure the position andorientation of the elbow and wrist relative to the location of theshoulder (e.g. the top of the humerus bone). When combined, thesesensors can provide a reference frame utilizing the Earth's localgravitational (center of Earth) and magnetic (magnetic north) fields.Using this reference frame in conjunction with a defined 3-axisCartesian coordinate system, different joints can be located in bothposition (X, Y, Z) and orientation (ψ (yaw), θ (pitch), φ (roll))relative to the origin of the Cartesian coordinate system at theshoulder using these same MEMS sensors. Adjacent MEMS sensors can beplaced at strategic locations where the length between sensors does notchange (or the change is a sufficiently small amount) when the jointsare bent or rotated. For example, sensors can be placed at locations onthe shoulder, elbow, and wrist where the distance between adjacentsensors remains fixed due to fixed bone lengths.

The calculation of position and orientation of each joint may use the3-axis Cartesian coordinate system and reference frame, the fixeddistance between adjacent sensors, and the 3-axis output signals fromthe accelerometers or magnetometers. Calculations may involve directioncosine matrices, Euler transformations, or matrix multiplication. Forsensors that are not adjacent to the origin, their coordinates may betransformed back to the coordinate system origin through intermediatetransformations between adjacent sensors. For example, if there aresensors at the shoulder, elbow, and wrist then the elbow coordinates canbe calculated directly relative to the origin (shoulder), but the wristcoordinates must first be calculated relative to the elbow coordinatesand then calculated again relative to the origin. The reason for this isbecause the path lengths must be known for each sensor location and theonly way to do this is by coordinate transformations along fixed lengthpaths (e.g., wrist to elbow and elbow to shoulder).

A wide range of MEMS sensors with integrated 3-axis accelerometers andmagnetometers may be used. Examples of manufacturers of these devicesinclude Analog Devices, Bosch, Freescale, Honeywell, and STMicroelectronics. Also, 9-axis sensors available with integrated 3-axis,accelerometers, magnetomers, and gyros may be used. Additional solutionsmay exist for joint locations where a fixed bone length cannot becounted on such as the hand and fingers.

In a second sensor aspect, a capacitive sensor may comprise a flexibleinsulating dielectric layer with thin flexible electrodes on eitherside. A voltage differential is applied between the electrodes, creatinga capacitor. When the dielectric changes shape (e.g. due to pressure orbending), the capacitance of the sensor changes and can be detected byelectronic measuring techniques. Capacitive pressure sensors may be usedin a variety of mechanical systems to measure barometric pressure orpressures inside equipment. Such sensors may be incorporated into thesleeve at joints (e.g. wrist, elbow) such that bending of the jointstretches or bends the dielectric layer. The sensors may also be appliedaway from joints (e.g. middle of the forearm) to measure the pressure ofthe sleeve against the arm.

In a third sensor aspect, resistive bend or stretch sensors (e.g. straingauges) may be used. These sensors may be made from any material thatchanges electrical resistance when stretched or strained. This change inresistance is measured with a standard electrical circuit. Strain gaugesmay use metal, either alone or applied to a flexible thin filmsubstrate. Resistive bend sensors or strain gauges also can be made fromthe following three general classes of materials. First, elastomers(such as silicone rubber) or polymers containing electrically conductivefillers may be used. Fillers can include carbon black, graphite,graphene, carbon nanotubes, silver nanoparticles, silver nanowires.Second, inherently conductive polymers may be used. Third, piezoelectricpolymers may be used.

Resistive sensors may also be applied at joints. Bending of the jointwill stretch the sensor, causing a measurable change in resistance.Pronation and supination of the wrist can be measured by using sensorsin the form of long elastic bands that stretch at an angle from thewrist to the elbow. Each motion (e.g. pronation and supination) willcreate opposite effects in the bands, causing one to lengthen and theother to shorten.

In a fourth sensor aspect, resonant bend sensors may be used. Resonantbend sensors comprise RLC circuits that change resonance frequency whenone of the three components changes its value. Rather than having aseparate circuit to measure the resistance of each resistive sensorelement, the resistive sensors may be wired in parallel at appropriatelocations in the neural sleeve. Each sensor may have a differentresistance to produce a different resonant frequency in the circuit. Asweep of voltage or current may be used to test each sensor in rapidsuccession; this measures changes in resonant frequency to determinechanges in resistance and thus in strain of that specific sensor.

In a fifth sensor aspect, a sensor may comprise numerous trapped volumes(e.g. fluid bladders) containing air or liquid that respond to changesin motion. For each motion to be detected, a fluid bladder of aspecifically designed shape would be placed at an appropriate locationsuch that the pressure in the bladder would change only in response tothat motion. For example, there may be one bladder at the wrist in aposition and shape to detect wrist flexion, while a different bladder atthe wrist detects pronation. Sensing elements, such as pressuretransducers or strain gauges, would respond to the pressure changes.

In a sixth sensor aspect, bend sensors also can be made from fiberoptics rather than electrical components. The principle is similar tothe electronic bend sensors in that when the fiber is bent, a measurableproperty such as frequency or attenuation changes and this change can bemeasured. The usage would be similar to the bend sensors describedabove, with fiber optic bend sensors integrated into the sleeve atjoints such as the wrist, such that the sensor bends with bending of thejoint.

In a seventh sensor aspect, a variety of video motion tracking systemsmay be used to measure and track the position of the limb while usingthe neural sleeve. These systems are similar to the ones used for motioncapture in movies and video games. One or more cameras may focus on thesleeve during use. To provide the best accuracy, these systems wouldinclude markers at key locations on the sleeve to be tracked. Dependingon the type of marker selected, the camera may operate in visible lightor infrared. A number of options are available for markers, including:(i) dots in a contrasting color or multiple distinct colors that can betracked by the external camera(s) (similar to typical movie motioncapture); (ii) colored light emitting diodes (LEDs); (iii) Infrared (IR)LEDs at various frequencies in the near-IR range; and (iv) thermalelements such as electrically resistive heaters that create localizedwarm spots to be tracked by a camera sensitive to long wavelengthinfrared (LWIR).

FIG. 29 is a perspective illustration of a neural sleeve 2910 showinghow various sensors could be placed thereon and implemented. The neuralsleeve extends from the shoulder down to the wrist. First, a trio ofMEMS sensors 2920, 2922, 2924 are located at the shoulder, elbow, andwrist, respectively. These can be used to measure position andorientation relative to each other. Next, a capacitive sensor 2930 islocated at the elbow. Resistive bend sensors 2940, 2942 stretch at anangle from the wrist to the elbow. Motion will create opposite effectsin these sensors, causing one to lengthen and the other to shorten.

As discussed above, it is contemplated that the neural sleeve will bemade of a reusable outer component and an inner component that can beeasily disposed of. The inner component comprises a conductive mediumthat contacts the electrodes present in the outer component and providesa conductive interface/medium between the electrode and the user's skin.

In particular embodiments, the conductive medium can be a hydrogel, or alotion, or a conductive polymer. In some embodiments, the conductivemedium is more conductive in a z-direction and less conductive in eitherof a x-direction or a y-direction. Put another way, the conductivemedium may become more conductive upon application of external pressure,in the direction of external pressure. This property can be obtainedfrom a compressible polymer and a conductive filler dispersed in thecompressible polymer. The conductive filler can be in the form of carbonfibers, carbon nanotubes, or metallic particles such as silver, gold,platinum, or palladium. The conductive filler is sparsely distributed inthe polymer so that when pressure is applied, the conductive fillersmake contact with each other and provide a conductive path from theelectrode to the skin. Other conductive hydrogels include a cross-linkedalginate polymer or a cross-linked polymeric hydrogel.

In alternative embodiments, to facilitate attachment to a patient, theconductive medium may be selected such that it becomes more tacky orsticky upon application of an electrical current, a change intemperature, a change in pH, or a change in moisture. The conductivemedium may be a stimuli-sensitive polymer. To further facilitateattachment and/or delivery of electrical simulation, the electrodes mayinclude concentric rows of teeth about 200 μm to about 300 μm in height.

If desired, the neural sleeve may be configured for gesture control ofvarious devices. Examples of devices that may be controlled are: acomputer cursor; an automatic remote; and a haptic interface. Thegesture control aspects are also used in virtual reality applications.Gesture control is facilitated by the addition of sensors on theneuromuscular stimulation device/neural sleeve. It is noted that theelectrodes present in the neural sleeve for stimulation can also be usedfor sensing.

In another aspect, a neural sleeve device is used to supportgait-training. To facilitate this, the neural sleeve would be adapted tocover both a leg portion and a foot portion of the patient. This allowsthe neural sleeve to cover both the muscles and the joint of a patient,and advantageously allows for sensing of a foot flexing. A hip portionmay also be covered; this allows for stimulation of additional areas topromote recovery following surgery.

In yet another aspect, neuromuscular stimulation may be delivered to thebackside of the patient. To facilitate this, the neuromuscularstimulation device may be in the form of a shirt, vest, garment, belt,or so forth, with the electrodes appropriately placed to contact thebackside.

The neuromuscular sleeve/neural sleeve could be operated in a wireless,battery-operated mode. In this case, the battery pack and theelectronics module can be strapped on the upper arm of the subject inthe form of an arm band. The device can be connected to the user'smobile device and/or PC for data transfer and real timetracking/monitoring.

It will further be appreciated that the disclosed techniques may beembodied as a non-transitory storage medium storing instructionsreadable and executable by a computer, (microprocessor ormicrocontroller of an) embedded system, or various combinations thereof.The non-transitory storage medium may, for example, comprise a hard diskdrive, RAID or the like of a computer; an electronic, magnetic, optical,or other memory of an embedded system, or so forth.

The processes and systems of the present disclosure are illustrated inthe following non-limiting examples.

EXAMPLES

FIGS. 30A-41B are pictures taken from a set of experiments where anable-bodied user's left hand was wrapped with a neuromuscular electricalstimulation sleeve. The user was asked to move his hand into differentpositions. In each set, one picture shows an image of the hand/armmotion that the user performed with his limb, and the other pictureshows a graphical hand representation of the user's limb position basedon position sensor data collected from the sleeve. In each set ofpictures, the actual limb moved is shown as the left hand, and thegraphical limb moved was the right hand. This was due to the setup ofthe system. As seen here, the correspondence between the measuredposition shown by the graphical limb and the actual limb movementcorresponded very well.

FIGS. 42A-42C are bar graphs showing the different percentages ofcurvature for each digit during finger extension, finger fair curvature,and making a fist. As seen in FIG. 42A, the digits were generallystraight for finger extension, with only three digits having anycurvature, and all of them being less than 20% curvature. In FIG. 42B,all of the digits were curved about halfway during finger faircurvature. In FIG. 42C, all of the digits were curved near theirmaximum, as desired. These illustrate the accuracy of the positionsensors and the software that processes their output.

The present disclosure has been described with reference to exemplaryembodiments. Obviously, modifications and alterations will occur toothers upon reading and understanding the preceding detaileddescription. It is intended that the present disclosure be construed asincluding all such modifications and alterations insofar as they comewithin the scope of the appended claims or the equivalents thereof.

1. A device for neuromuscular stimulation and/or electromyography (EMG)recording, the device comprising: a sleeve comprising a compressionsleeve fabric; and electrodes housed within the sleeve.
 2. The device ofclaim 1, wherein the electrodes are woven into the sleeve usingconductive threads or fibers.
 3. The device of claim 2 wherein theconductive threads or fibers are woven into the sleeve.
 4. The device ofclaim 1, wherein the electrodes are printed on the sleeve.
 5. The deviceof claim 4, wherein the electrodes comprise conductive polycellulose orsilver-based or carbon-based or silver/carbon-based ink.
 6. The deviceof claim 1, further comprising: buttons comprising light emitting diode(LED) based touchscreen displays on a back side of each of theelectrodes.
 7. The device of claim 1, further comprising: a userinterface comprising buttons on an exterior of the sleeve.
 8. The deviceof claim 1, further comprising: a user interface on an exterior of thesleeve for controlling individual electrodes or groups of electrodes. 9.The device of claim 1, further comprising: a user interface on anexterior of the sleeve for configuring the electrodes or adjusting astimulation level or pattern.
 10. A method of manufacturing a device forneuromuscular stimulation and/or electromyography (EMG) recording, themethod comprising: providing a sleeve comprising a compression sleevefabric; and securing electrodes within the sleeve.
 11. The method ofclaim 10 wherein the securing of the electrodes within the sleevecomprises: weaving the electrodes into the sleeve using conductivethreads or fibers.
 12. The method of claim 10 wherein the securing ofthe electrodes within the sleeve comprises: printing the electrodes onthe sleeve.
 13. The method of claim 10 wherein the securing of theelectrodes within the sleeve comprises: printing the electrodescomprising conductive polycellulose or silver-based or carbon-based orsilver/carbon-based ink on the sleeve.
 14. The method of claim 10,further comprising: disposing buttons comprising light emitting diode(LED) based touchscreen displays on a back side of each of theelectrodes.
 15. The method of claim 10, further comprising: disposing auser interface comprising buttons on an exterior of the sleeve.
 16. Themethod of claim 10, further comprising: controlling individual or groupsof the electrodes using a user interface disposed on an exterior of thesleeve for controlling.
 17. The method of claim 10, further comprising:configuring the electrodes or adjusting a stimulation level or patternusing a user interface disposed on an exterior of the sleeve.
 18. Adevice for neuromuscular stimulation and/or electromyography (EMG)recording, the device comprising: a sleeve comprising a compressiblefabric material; and electrodes woven into the compressible fabricmaterial of the sleeve using conductive threads or fibers.
 19. Thedevice of claim 18 wherein the conductive threads or fibers are woveninto the fabric material of the sleeve.